Cam operated retarded timer switch assembly with dashpot type air timer unit

ABSTRACT

This invention relates to a combined, pneumatic, mechanical and electrical control timer mechanism including an air timer unit which comprises a resilient diaphragm having its outer periphery fixedly attached to said casing a compression spring mounted in the interior of said casing so as to urge resiliently said diaphragm in its inflating direction, an opening bored through said casing for establishing fluid communication between the interior space of said casing, the ambient atmosphere, and a pervious member covering said opening for limiting fluid passage through said opening, and a check valve means provided on said casing for checking invasion of ambient atmosphere from outside into the interior of said casing, yet, allowing the reverse air flow. The mechanism comprises further a cam shaft which carries a first, a second and a third cam. The third cam is an operation instructing member for control of a separate machine or instrument, such as the medicament sprayer. The first and second cams control a normally closed contact pair which is inserted in the circuit in the circuit for an electric motor geared to said cam shaft. The second cam is arranged to reset the air timer unit. The first cam acts upon the contact pair to open only after the second cam has completed the reset operation for the air timer unit.

" United States Patent [19] Yokoyama 1 June 5, 1973 [54] CAM OPERATEDRETARDED TIMER SWITCH ASSEMBLY WITH DASIIPOT TYPE AIR TIMER UNIT [75]inventor: Eisuke Yokoyama, Musashino-shi,

Tokyo,Japan [73] Assignee: Kawaguchiko Seimitsu Kabushiki Kaisha,Minami-tsura, Japan 221 Filed: Deal 3,1971

21 Appl.No.: 207,391

[30] Foreign Application Priority Data Dec. 12, 1970 Japan ..45/l2358652] U.S. Cl. ....200/34, 200/33 B 51 int. Cl. ..H01h 1/03, l-lOlh 43/00[58] Field of Search ..200/33 R, 33 B, 34,

[56] References Cited UNITED STATES PATENTS 2,366,454 1/1945 Pattee..200/33 B Primary Examiner-J. R. Scott Att0rney- Richard C. Sughrue,Gideon Franklin RothwelLJohn H. Mion 1 [57] ABSTRACT This inventionrelates to acombined, pneumatic, mechanical and electrical control timermechanism including an air timer unit which comprises a resilientdiaphragm having itsouter periphery fixedly attached to said casing acompression spring mounted in the interior of said casing so as to urgeresiliently said diaphragm in its inflating direction, an opening boredthrough said casing for establishing fluid communication between theinterior space of said casing, the am bient atmosphere, and a perviousmember covering said opening for limiting fluid passage through saidopening, and a check valve means provided on said casing for checkinginvasion of ambient atmosphere from outside into the interior of saidcasing, yet, allowing the reverse air flow. The mechanism comprisesfurther a camshaft which carries a first, a second and a third cam. Thethird cam is an operation instructing member for control of a separatemachine -or instrument, such as the medicament spray'eL The first andsecond cams control a normally closed contact pair which is inserted inthe circuit in the circuit for an electric .motor geared to said camshaft. The second cam is arranged to reset the air timer unit. The firstcam acts upon the contact pair to open only after the second cam hascompleted the reset operation for the air timer u'nit.

3 Claims, 4 Drawing Figures CAM OPERATED RETARDED TIMER SWITCH ASSEMBLYWITH DASI-IPOT TYPE AIR TIMER UNIT This invention relates generally totimers. More specifically, it concerns with a timer mechanism with anair timer unit, said mechanism being adapted for use in various fields,such as, for instance, intermittent spraying of dosed quantities offungicidal liquor on the culturing field.

Conventional timers comprise frequently as the time control unit amechanical or electric timepiece having a driver, preferably in the formof a power spring or an electric motor. In other known timer mechanisms,they operate by the way of thermal response. Others operate by gravity,fluid pressure or the like.

The use of power spring, however, invites a troublesome and frequentwinding-up operationJWith use of the commercial current source, a localand independent utilization of the timer, for instance on the culturefields may be frequently impossible.

It is therefore the main object of the present invention to provide anoperation control timer devoid of the aforementioned conventionaldrawback. More specifically, it is aimed at by the present invention toprovide an operation control timer of a simple design and arrangementhaving a self-contained power source or I battery, in combination with ad.c. motor as the drive means and in combination with an air-operatedtime control unit.

. The term air timer unit as used herein throughout the specificationand appended claims means such a type of timer which comprises aresilient diaphragm having its outer periphery fixedly attached to saidcasing, a compression spring mounted in the interior of said casing soas to urge resiliently said diaphragm in its inflating direction, anopening bored through said casing for establishing fluid communicationbetween the interior space of said casing, the'ambient atmosphere, and apervious member covering said opening for limiting fluid passage throughsaid opening, and a check valve means provided on said casing forchecking invasion of ambient atmosphere from outside into the interiorof said casing, yet allowing the reverse air flow. The pervious membercan be made of paper sheet, foam resin mass, cellophane sheet, poroussintered alloy mass, textile fiber mass, felt sheet, porous ceramic massor the like.

A salient feature of the mechanism according to the present inventionresides in that during the limited time interval, such as several tensminutes as an example, any power source such as current source, powerspring or the like, is not operated and the power is consumed only forthe resetting job. The energy dissipated during the resetting period ispreserved in spring means contained in the timer unit. The release ofthe thus accumulated spring energy is braked by limiting the airinvasion from outside of the timer unit through a highly limited fluidpassage barrier such as pervious sheet, porous mass, or the like, intothe interior of said timer unit. The reset drive mechanism comprises anelectric motor, a current source connected therewith, a cam shaftoperatively connected with said motor and carrying thereon three cams.When the cam shaft is rotated by actuation a main switch inserted in themotor circuit, the first one of said cams operates upon thediaphragmspring combination of the air timer unit so as to reset thelatter through a certain intermediate member preferably formed into afirst lever. A pair of switch contacts are provided in the motorcircuit, the movable one of said contacts being mechanically connectedwith the diaphragm so as to be on-off controlled thereby.

The second cam operates through a second intermediate member, preferablymade into a lever, ,onthe movable contact.

The configurations and operational phases of these two cams are soselected that the timer unit has been reset so as to depress thediaphragm-spring combination to its most-compressed position and toexert its effort to displace the movable contact to its off-position,the second cam acts upon the contact so as to maintain nevertheless thecontact at its on-position for the time being, yet to bring it in itsoff-position after lapse of a certain initial presetting period. Bybringing the mov-- able contact into its interrupted position, the motorcircuit is kept in off-service in spite of the on-position of the mainswitch. l

A certain prescribed time interval has elapsed, the air timer unit isbrought into the actuating position upon consuming the accumulatedspring energy devoid of the initially loaded energy. Upon actuation ofthe timer unit so as to close the electric contacts for initiation ofthe rotational movement of the cam shaft by energization of the motorcircuit, the third cam is brought into its actuation so as to perform anoperation control job for initiation of the operation of a certaininstrument, machine, or the like. V

These and further objects, features and advantages of the invention willbecome more apparent when read the following detailed description of theinvention by reference to the accompanying drawing illustrativesubstantially of a preferred sole embodiment of the invention. v

In the drawing 2 p FIG. 1 is a schematic sectional view of a timecontrol unit employed in the operation control timer mechanism accordingto the invention positioned, however, in its reset position.

FIG. 2 is a similar view to FIG. 1, illustrative, however, of the unitin its operational position;

FIG. 3 is a schematic perspective view of an operation control timer asa whole, embodying the principles of the invention.

FIG. 4. is a timing chart showing mutual operational phases of severalworking parts of the mechanism shown in the foregoing. 1

Referring now to the accompanying drawing, the time control unit,generally shown at 7, comprises a diaphragm piston l which has aflexible diaphragm disc 1a and a thickened central part lb, said partsbeing made integral with each other and the whole being made of aresilient and unpervious material such as soft rubber, plastics or thelike. 7

Numeral 3 represents a rigid housing of unit 7, being made into adish-shaped member which is made preferably of metal, hard plastic orthe like. The housing 3 is formed at its top with an inwardly directingperipheral flange 3a for detachably fastening the peripheral zone of thediaphragm disc 10 by inserting under pressure a 1 spring clip 6 formedinto an open ring. Or alternatively, a male-screwed cap may be used uponforming female screw threads on the upper portion of the insideperipheral wall surface of the housing 3, although not shown.

In this way, air chamber isformed in the interior space of the unit 7,by being defined by the diaphragm piston l and substantial part of theinside wall surface of the housing 3, as shown.

A coil spring 2 is provided within the interior or air space 5 andbetween the central thickened part lb of the diaphragm piston and thebottom 3b of housing 3, for urging the diaphragm in its inflating andexpanding direction.

' Between the opposing ends of the spring clip 6, there is provided witha gap which is normally closed by a part of the peripheral zone of thediaphragm, so as to form a check valve 26 thereat, as will be more fullydescribed hereinafter. However, if necessary, a separate check ornon-return valve means may be provided through the wall of housing 3,for allowing air discharge therethrough during the reset period to beset forth.

At the center of the housing bottom 3b, there is provided a fluidpassage opening 25 which is surrounded with ample idle gaps by a barrierholder 27 which is fixed to the housing bottom 3b by set screws, glueingor the like conventional means although not shown. A small inside space27a is formed within the holder 27 and contains a piece of a perviousmaterial which provides a substantially air flow limiting or barriereffect when air flow is allowed to pass therethrough as will be morefully described hereinafter. A passage bore 29 is drilled through thebarrier holder 27 so as to establish air flow from the ambientatmosphere into the air chamber 5 and in the reversed sense as occasionmay desire to be more specifically described. The material for thebarrier piece was already referred to hereinbefore by way of example. Inthe mechanism shown in FIG. 3, an electric drive motor 11 is providedand connected electrically through battery 21 and main switch 22 with apair of electrical contacts 9 and 10, so as to provide a motor circuitas shown. Contact 9 is a movable one, while contact 10 is a stationaryone although its fixedly mounting means have been omitted from thedrawing only for simplicity.

The drive motor 11 has a motor shaft 11a which is mechanically coupledthrough a reduction gearing, generally shown at 12, with a cam shaft 13carrying three cams 14, 15 and 16 and rotatably mounted in end bearings30 and 31.

The first cam 14 of the said three cams is arranged to act upon afollower lever 17 which is pivotably mounted at an intermediate point 32between its opposite ends. The movable contact 9'is shaped substantiallyinto a resilient tee and made of a resilient material and having a lefthand arm 9b and a right hand arm 9a, the outer end of the former armbeing kept normally in pressure contact with the tip end of the firstlever 17, preferably through an insulating sheet positioned between theboth, although not shown. The first end of lever 17 which is kept incontact with the first cam 14 is urged by a coil or pressure spring 33,as shown.

Second cam 15 is arranged as shown, to actuate upon a second switchlever 8 which is pivotably mounted at 19 and fitted with a tensionspring 23 provided at a proximity to the related cam.

The outer end of arm 9b is kept in contact with the top end of thethicked central portion la of the diaphragm piston 1 by the tip end ofsecond switch arm 8. With air timer unit 7 positioned in advance ofresetting and with the first and second cams l4 and 15 having theirrespective cam rise portions 14a and 15a positioned at their off-serviceposition as shown, the stationary and movable contacts proper A and Bcarried on respective tip ends of contact members 10 and 9,respectively, are kept in their mutually closed position. The dimensionsand arrangements of several parts related with the switch contacts A andB, and those of the air timer unit 7, especially the diaphragm piston land spring 2, are selected to satisfy this requirement. This off-serviceposition of the unit 7 is shown in FIG. 2 and that of the wholemechanism is shown in FIG. 3, respectively. The spring force at 23 isselected to be substantially smaller than that at 2.

The timing diagram of several working parts is shown in FIG. 4 as anexample.

The operation of the mechanism so far shown and described is as followsI With the operational parts positioned in FIGS. 2 and 3, the mainswitch 22 is now closed manually. Since both contacts proper A and B areclosed with each other, current is conveyed from current source 21 todrive motor 11 and thus, the latter is caused to rotate. Motion is nowtransmitted from drive motor 11 through gearing 12 to cam shaft 13. Withrotation of camshaft 13, and during the initial portion of the cam shaftrotation, the third cam 16 which is mechanically v ormechano-electrically with a certain machine, such as a medicamentsprayer by way of example, the operation of which is to be controlled bythe mechanism according to this invention, delivers a certaininstruction signed to the machine. As an example, the machine isactuated to initiate a spraying operation by being pushed down itsactuating push button.

With further rotation of cam shaft 13, the cam rise portion 14a isbrought into pressure contact with the root end of first switch lever17, thus the tip end thereof being raised in its position. Therefore,the contact arm 9a is flexed resiliently, while the contacts proper Aand B are kept in closed position.

Next, second cam 15 is brought into actuation so that the second switchlever 8 is depressed by contact with cam rise portion 15a, thereby thetip end of said lever depressing the diaphragm piston l and the spring 2of timer unit 7 for performing the resetting operation therefor. Uponcompletion of this resetting operation, second cam rise portion 15a isbrought into separation from contact with second switch lever 8. Theunit 7 now takes the position shown in FIG. 1. During this resettingoperation, the contacts proper A and B are kept in contact as before.Only after lapse of a certain short time period, the first cam riseportion is receded from contact with the related switch lever 17, so asto separate contacts proper A and B from each other for de-energizingthe motor circuit.

The rotation of cam shaft 13 is terminated upon performing substantiallya complete revolution thereof.

The duration period of the operation instruction signal delivered underthe action of third cam 16 can be terminated at a proper time dependingupon the cam configuration thereof, and in advance of the deenergizationof the motor circuit.

During the presetting period, air will escape through the non-returnvalve formed at 26.

Upon completion of the resetting operation for the unit 7 in theaforementioned way, the preset and thus compressed-down diaphragm springcombination will recover gradually its original non-compressed state,the

necessary time period for such full recovery depending upon the size ofthe opening 29 and the degree of perviousness of the material at 28.This member 28 can be, when necessary, attached fixedly to the bottomsurface of the lower wall 3b, so as directly to cover the passage at 25.In this case, the member 27 can be removed from the mechanism.

The aforementioned on-off control operations can be repeated until themain switch 22 will have been intentionally cut off by the operator.During this repeated on-off control operation, operation control signalsby the action of the third cam 16 will be delivered repeatedly atregular time intervals corresponding to the re- .covery periods of thesaid diaphragm and spring combination.

Although not shown only for simplicity of the drawing, the mechanismshown in FIG. 3 comprises a stationary housing member which supportsrigidly the several members of the mechanism, such as those shown at 10,ll, 19, 23, 30, 31, 32 and 33. This housing is provided with anintermediate and perforated bottom 100 only partially shown, whichsupports the air timer unit 7 stationarily, as clearly seen from FIGS. 1and 2.

. For completeness, the movable switch 9 is pivotably supported at itsroot end, as schematically shown at for periodically engaging saidmovable contact to close said switch means, and a second switching armmeans operably disposed between said movable contact and said second cammeans for periodic movement to a position allowing said movable contactto open said switch means, said third cam means being adapted to controla timed output response, said air timer unit being comprised of acasing, a resilient diaphragm .having an outer periphery fixed to saidcasing, a compression spring mounted in the interior of said casing soas to resiliently urge said diaphragm outwardly from said casing, anopening bored through said'casing for establishing fluid communicationbetween the interior of said casing and the ambient atmosphere, apervious member covering said opening for limiting fluid passage throughsaid opening, and check valvemeans provided on said casing allowing onlyair flow from the inside of said casing to the outside thereof, saiddiaphragm being disposed in engagement with said second switching armadjacent said movable contact member for normally biasing said movablecontact member to close said switch means under the influence of saidspring, said second cam means adapted to periodically shift said secondswitching arm to compress said spring and allow said movable contactmember to open said switch means'with said first cam means and'saidfirst switching arm are not holding said movable contact in a positionto close said switch means. 2. An operation control timer mechanism asset fort in claim 1 wherein said first switching'arm is pivotedintermediate the ends thereof with one of said ends being disposed inoperative engagement with said movable contact and spring means biasingthe other of said ends into operative engagement with said first cam

1. An operation control timer mechanism comprising an air timer unit, arotatable cam shaft carrying first, second and third cam means rigidlythereon, an electric motor operatively connected to said shaft havingcircuit means including a power source and switch means comprised of astationary contact and a movable contact, a first switching arm meansoperably disposed between said movable contact and said first cam meansfor periodically engaging said movable contact to close said switchmeans, and a second switching arm means operably disposed between saidmovable contact and said second cam means for periodic movement to aposition allowing said movable contact to open said switch means, saidthird cam means being adapted to control a timed output response, saidair timer unit being comprised of a casing, a resilient diaphragm havingan outer periphery fixed to said casing, a compression spring mounted inthe interior of said casing so as to resiliently urge said diaphragmoutwardly from said casing, an opening bored through said casing forestablishing fluid communication between the interior of said casing andthe ambient atmosphere, a pervious member covering said opening forlimiting fluid passage through said opening, and check valve meansprovided on said casing allowing only air flow from the inside of saidcasing to the outside thereof, said diaphragm being disposed inengagement with said second switching arm adjacent said movable contactmember for normally biasing said movable contact member to close saidswitch means under the influence of said spring, said second cam meansadapted to periodically shift said second switching arm to compress saidspring and allow said movable contact member to open said switch meanswith said first cam means and said first switching arm are not holdingsaid movable contact in a position to close said switch means.
 2. Anoperation control timer mechanism as set forth in claim 1 wherein saidfirst switching arm is pivoted intermediate the ends thereof with one ofsaid ends being disposed in operative engagement with said movablecontact and spring means biasing the other of said ends into operativeengagement with said first cam means.
 3. An operation control timermechanism as set forth in claim 1 wherein said second switching arm ispivoted at one end thereof with the opposite end being disposed betweensaid flexible diaphragm and said movable contact, said second switchingarm being disposed for engagement by said second cam means at a pointintermediate the ends of said arm and spring means normally holding saidarm in engagement with said flexible diaphragm.